The invention relates to an image processing system for a vehicle, including a first unit, a second unit and a video transmission link, which couples the first unit and the second unit in terms of signaling for transmitting digital video data.
In a vehicle, such as in a motor vehicle, an increasing amount of information is provided to the vehicle user and/or vehicle driver by way of visual output devices. However, due to the multitude of visual output devices, which are increasingly designed as displays, it is difficult for a vehicle user and/or vehicle driver to reliably gather the most important information from a number of simultaneously presented individual images and/or video images.
It is the object of the invention to create an image processing system for a vehicle which makes a contribution to improving the depiction of video images.
This and other objects are achieved according to the invention, by providing an image processing system for a vehicle, comprising a first unit, a second unit and a video transmission link, which couples the first unit and the second unit in terms of signaling, for transmitting digital video data. The video transmission link is designed to transmit digital video image signals having a predefined data format for a respective pixel of a video image, the data format comprising three blocks, each having a predefined number of bits. The first unit is designed to transmit an uncompressed, transformed video image signal suitable for transmission via the video transmission link as a function of a respective first video image signal in such a way that the transformed video image signal has the predefined data format of the video transmission link. The first video image signal represents respective uncompressed first video images of a sequence of first video images, which are provided at a predefined frame rate and which in each case have a first image resolution having a predefined number of pixels, wherein in each case four pixel values are assigned to the respective pixels of the first video image. The second unit is designed to again ascertain the first video image signal as a function of the transformed video image signal received via the transmission link.
Advantageously, this allows digital video images, which include an alpha channel in addition to three color channels, for example, to be transmitted in uncompressed form via a video transmission link, which otherwise is only provided for transmission of uncompressed video images having three color channels. Examples of such video transmission links provided for transmitting uncompressed video images having three color channels include, for example, a High Definition Multimedia Interface (HDMI) transmission link, a Digital Visual Interface (DVI) transmission link and/or an Automotive Pixel Link (APIX).
Advantageously, this allows the first video images to be made available for further devices in the vehicle, which are suitably designed, for example, for visually displaying the first video images and/or which are designed to merge the first video images and further video images generated by the further and/or other units to form a fused image. This makes it possible to suitably combine information from different images generated by different sources in a fused image.
In an advantageous embodiment, a first pixel value representing a red color, a second pixel value representing a green color, a third pixel value representing a blue color, and a fourth pixel value representing transparency are assigned to the respective pixel of the first video image. Thus, three color channels and one alpha channel are assigned to the pixel. The alpha channel is an additional channel that represents the transparency of the individual pixels in raster graphics, in addition to the color information. A distinction is made between a direct alpha channel and an external alpha channel. The image processing system according to the invention allows the first video images to have a direct alpha channel, in which the respective transparency information is stored in a separate channel, in addition to the color channels. In the case of a direct alpha channel, a pixel is thus stored using not only three values, for example using a respective value for red, green and blue, but using four values, such as a respective value for red, green, blue and transparency. For storage and/or transmission, no external alpha channel is required in which the transparency information is stored and/or transmitted as a separate file.
In a further advantageous embodiment, the second unit is designed to ascertain an overall video image signal as a function of the first video image signal, which has been ascertained again, and a second video image signal. The second video image signal represents respective second video images of a sequence of second video images, which are provided at a predefined second frame rate and which in each case have a second image resolution having a predefined number of pixels. In each case, three pixel values are assigned to the respective pixels of the second video image. The overall video image signal is ascertained in such a way that the overall video image signal represents respective image-in-image video images of a sequence of image-in-image video images. Advantageously, this allows first and second video images to be merged, so that the image-in-image video image has a higher useful information content and/or less interference than the first and/or second video images. The frame rate and the second frame rate can be selected to be identical. This allows for easy calculation of the overall video image signal. The frame rate and the second frame rate are preferably selected in such a way that a human eye is conveyed a flowing image impression by moving image contents.
In a further advantageous embodiment, the first pixel value representing the red color, the second pixel value representing the green color and the third pixel value representing the blue color are assigned to the respective pixel of the second video image. Advantageously, this allows for easy calculation of the respective image-in-image video images.
In a further advantageous embodiment, the overall video signal is ascertained in such a way that a weighting of an overlay of the respective pixels of the first video image and of the second video image is carried out as a function of the fourth pixel values of the first video image representing the transparency. Advantageously, this allows the respective first video image to be inserted into the respective second video image in such a way that no transitions between the respective first video image and the respective second video image are visible to an observer of the respective image-in-image video images when the image-in-image video images are displayed by way of an output device. Moreover, this makes it impossible for an observer to detect which unit provides which image contents in the respective image-in-image video image.
In a further advantageous embodiment, the first unit is designed to generate the first video image signal. This enables a compact design of the image processing system.
In a further advantageous embodiment, the second unit is designed to generate the second video image signal. Advantageously, this also enables a compact design of the image processing system.
In a further advantageous embodiment, the first unit is designed to convert the respective first video image signal into the transformed video image signal in such a way that the transformed video image signal represents a transformed video image, which has the same pixel values as the first video image and a number of pixels greater by a factor of 4/3 than the first video image and in which in each case three pixel values are assigned to the respective pixels of the transformed video image. Advantageously, this makes it possible with very low computing complexity to convert the first video image signal into the transformed video image signal, so that the transformed video image signal has the predefined data format of the video transmission link. One of the three pixel values can be assigned to the respective block of the three blocks. For example, the number of bits of the blocks can be six or eight. The number of bits can be predefined as a function of a desired value range of the respective pixel values.
In a further advantageous embodiment, the first unit is designed to convert the respective first video image signal into the transformed video image signal in such a way that three consecutive pixels of the first video image in each case are covered by four consecutive pixels of the transformed video image. Advantageously, this allows for the first video image signal to be converted into the transformed video image signal using only very low computing complexity. Moreover, this has the advantage that a proportion of pixel values requiring buffering can be minimized.
In a further advantageous embodiment, an order is assigned to the pixel values of the first video image, and the first unit is designed to convert the respective first video image signal into the transformed video image signal in such a way that the pixel values of the transformed video image have the same order. Advantageously, this allows for the first video image signal to be converted into the transformed video image signal using only very low computing complexity. Moreover, this has the advantage that no resorting of the pixel values is required, and thus any necessary buffering of the pixel values can be eliminated.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.